Thread: 'Subsonic' .22 ammo going off with a crack

I have heard (so take it with a yearly serving of salt) that gunpowder burns faster the older it gets. So if you had some sub-sonics that were close to breaking the sound barrier when they were made you might have a few cracking through it now they're older. Even now when I buy .22 subs occasionally 4 or 6 rounds still breach. So, hard to know for sure, but that's an idea.